Variable-rate spring marine docking cable

ABSTRACT

The variable-rate spring marine docking cable is a device for allaying the shock forces on moored floating structures due to wind, wakes, tides and storms. The device includes a variable-rate spring member similar to an automobile strut. Respective cables are attached at first ends to each respective end of the spring member. One of the cables is attached at its second end to a floating structure such as a dock or boat. The other cable is attached at its second end to a mooring pile, pier, or other fixed object.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/213,823, filed Jul. 20, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to tethers and to marine ropesand cables, and particularly to a marine docking cable that includes ashock-absorbing device for dampening bi-directional forces that areproduced by water movement and the like on docks.

2. Description of the Related Art

The growth of costal and lakeside communities has greatly increasedinterest and participation in water sports (swimming, fishing, waterskiing, etc.). The increased activity in such sports has required thebuilding of moored docks in the waters adjacent the shorelines of lakesand streams. Unfortunately, wind, wakes, tides and storms result in dockmovement, which movement can produce shocks that cause damage to theramps, tie sections, etc. of the dock. Repairing the damage requires theexpenditure of time and money. If not repaired, the damaged dock cancause minor or severe injury. A device that could efficiently andeffectively allay the shock forces on the dock, due to the conditionsindicated above, would greatly reduce the incidence of damage, therebyreducing the cost of upkeep and the chances for injury. Thus, avariable-rate, spring marine docking device solving the aforementionedproblems is desired.

SUMMARY OF THE INVENTION

The variable-rate, spring marine docking cable is a device thatcomprises a coiled spring member similar to an automobile strut. In afirst embodiment, a plate is attached to each end of the spring. Eachplate is provided with an opening therethrough. A pair of parallel tubesis disposed within and extends along the length of the spring member.Each tube has an end that extends through the openings in the plates,the tubes extending through opposing plates. The other end of each tubeis attached to the inner surface the opposing plate. A respective cableextends through the interior of each tube. One end of each cable isformed as a loop. A clamp(s) is provided at the other end of each cable.The clamp(s) serves as a stop to prevent the cable from being pulledthrough the plate. One cable loop is attached to the boat, floatingdock, or other floating structure, and the opposite cable loop isattached to a mooring pile, pier, or other fixed object. In a secondembodiment, a pair of round bars, each of which is bent in substantiallya U-shape, replaces the tubes and cables within the coiled springmember. The mooring and docking cables are attached to the respectivebars. The above-described arrangements prevent the cables fromtightening too quickly when the forces produce sudden dock movement. Thecable spring is designed to keep both sides of the cable at the sametension so that the dock is not allowed to sway from side to side.

Accordingly, the invention presents a device for attenuating the forcesproduced on a moored dock, which forces are generated by the effects ofwater movement, storms, wind and the like. The device is constructed ofrugged material and is easy to use. Although indicated for use on docks,the device could also be applied to other floating structures such aspiers, boats, buoys, etc. The invention provides for improved elementsthereof in an arrangement for the purposes described that areinexpensive, dependable and fully effective in accomplishing theirintended purposes.

These and other features of the present invention will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an environmental, perspective view of a first embodiment of avariable-rate spring marine docking cable according to the presentinvention.

FIG. 2 is a perspective view of a first embodiment of a variable-ratespring marine docking cable according to the present invention.

FIG. 3 is an end view of a first embodiment of a variable-rate springmarine docking cable according to the present invention.

FIG. 4 is a partial side view in section of a first embodiment of avariable-rate spring marine docking cable according to the presentinvention, showing the cables extending through the tubes.

FIG. 5 is a perspective view of a second embodiment of a variable-rate,spring marine docking cable according to the present invention.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, the variable-rate spring marine docking cable,generally indicated at 10, is shown attached at a proximate end to afloating dock 12. The distal end of the device is attached to an end ofa mooring line 14. The other end of mooring line 14 is fastened to aconventional turnbuckle device 15 and mooring post 16.

As best seen in FIGS. 2-4, a first embodiment of the marine dockingcable 10 comprises a variable-rate spring member 20 (e.g., a helicalcompression spring), which is similar to an automobile strut. Plates 22and 24 are respectively attached at the opposite ends of variable-ratespring member 20. Each plate has an opening 22 a, 24 a formedtherethrough. Tubes 26 and 28 are positioned within the coils of springmember 20 and extend along the length thereof. Tube 26 has a first end26 a that extends through the opening 22 a in plate 22. The other end 26b of tube 26 is attached to the inner surface of plate 24, and defines asecond opening through plate 24. Conversely, tube 28 has a first end 28a that extends through opening 24 a in plate 24. The other end 28 b oftube 28 is attached to the inner surface of plate 22, and defines asecond opening in plate 22. Welds are preferred to effect the attachmentof the tube ends and spring coils to the plates. It is recognized,however that other means of attachment may be employed if deemedsuitable. A pair of docking cables 30, 32, or other elongated, flexiblemembers, extends through each tube 26 and 28. Clamps 34 are employed toform respective loops 30 a and 32 a in one end of each cable. The clamps34 are disposed at the ends 30 b, 32 b of each cable opposite the loopto prevent the cables 30, 32 from sliding through the tubes 26, 28 andthe corresponding plate 22, 24. Protective thimbles 36 are positioned onthe ends of each cable 30, 32 to prevent the cable 30, 32 from crimpingand fraying.

In use, the looped end of one cable is attached to the dock or otherfloating or movable object or structure. The other looped end isattached to a mooring cable, which is attached to a fixed object orstructure. The mooring cable is tightened so that the marine dockingcable 10 is positioned out of the water. This arrangement alleviates theincidence of rusting and prolongs the life of the device. Bi-directionalforces on the dock caused by the above-stated factors will cause thedevice to compress and decompress, thereby absorbing any sudden shockthat would be transmitted to the dock and preventing damage thereto. Theprogressive or variable-rate spring changes resistance as it compressesand becomes progressively stiffer as the load increases. The spring 20compresses and decompresses, acting as a brake, taking the shock out ofthe cable 10 as it tightens quickly due to windstorms or high waves. Thedevice is designed to keep each cable end at the same tension and notallow the dock or other floating or movable object or structure to swayside to side. As contemplated, the cable 10 will be packaged as a kit toinclude the above-described spring structure and turnbuckle.

As shown in FIG. 5, a second embodiment of the variable-rate springmarine docking cable employs a pair of round bars 42, 44 disposed withinvariable spring 20. Bars 42, 44 are bent in U-shaped configurations,having respective free ends 42 a, 44 a formed as hooks. The bight orbase 42 b of one bar 42 extends slightly beyond one end of the spring20, while the bight or base 44 b of the other bar 44 extends slightlybeyond the other end of spring 20, the bights being orthogonal to eachother so that the bight of one bar extends through the open mouth orthroat of the other bar. Respective free ends 42 a, 44 a are attached toopposite ends of spring 20 (preferably by welds). The mooring lines areattached to the device at the respective bases 42 b, 44 b employingthimbles 36 and turnbuckles 15 as needed.

It is to be understood that the present invention is not limited to theembodiments described above, but encompasses any and all embodimentswithin the scope of the following claims.

1. A variable-rate spring marine docking cable, comprising: avariable-rate compression spring member having a proximate end, a distalend, an axial length, and helical coils; a two-part cable having a firstpart extending from the proximate end of the spring and a second partextending from the distal end of the spring; means for compressing thecoil when a tensile force is applied to at least one part of thetwo-part cable, the means for compressing extending through the helicalcoils.
 2. The variable-rate spring marine docking cable according toclaim 1, wherein said compression spring member is a helical springmember.
 3. The variable-rate spring marine docking cable according toclaim 1, wherein said means for compressing comprises; a first plate anda second plate, each of the plates having an inner surface, an outersurface, and a pair of openings defined therein, the first plate beingattached to the proximate end of the spring member and the second platebeing attached to the distal end of the spring member; a first tubehaving a first end and a second end, the first end of the first tubebeing attached to the first plate and defining one of the openings inthe first plate, the second end of the first tube extending through oneof the openings in the second plate, the first part of the cableextending through the first tube; a second tube having a first end and asecond end, the first end of the second tube being attached to thesecond plate and defining one of the openings in the second plate, thesecond end of the second tube extending through one of the openings inthe first plate, the first and second tubes being parallel to each otherand extending coaxially through the helical coils, the second part ofthe cable extending through the second tube; and a first stop memberattached to the first part of the cable at the distal end of the springand a second stop member attached to the second part of the cable at theproximate end of the spring, the stop members bearing against thecorresponding plate to compress the end of the spring when the tensileforce is applied to the corresponding part of the cable.
 4. Thevariable-rate spring marine docking cable according to claim 3, whereinsaid the first and second parts of said two-part cable comprise dockingcables.
 5. A variable-rate spring marine docking cable according toclaim 1, wherein said means for compressing comprises a pair of round,metallic bars disposed extending through the helical coils, each of themetallic bars being U-shaped and having a base end and free ends, thefree ends being formed into hooks engaging the corresponding end of saidspring.
 6. The variable-rate spring marine docking cable according toclaim 5, wherein the first and second parts of said two-part cable areattached to the base end of a corresponding one of the U-shaped bars. 7.A variable-rate spring marine docking cable, comprising: a variablerate, helical compression spring member having a proximate end, a distalend, an axial length, and helical coils defining an inner volume; afirst plate and a second plate, each of the plates having an innersurface, an outer surface, and a pair of openings defined therein, thefirst plate being attached to the proximate end of the spring member andthe second plate being attached to the distal end of the spring member;a first tube having a first end and a second end, the first end of thefirst tube being attached to the first plate and defining one of theopenings in the first plate, the second end of the first tube extendingthrough one of the openings in the second plate; a second tube having afirst end and a second end, the first end of the second tube beingattached to the second plate and defining one of the openings in thesecond plate, the second end of the second tube extending through one ofthe openings in the first plate, the first and second tubes beingparallel to each other and extending coaxially through said volume; afirst docking cable extending through the first tube; and a seconddocking cable extending through the second tube.
 8. The variable-ratespring marine docking cable according to claim 7, further including apair of stop members disposed on said docking cables on opposite ends ofsaid spring.
 9. The variable-rate spring marine docking cable accordingto claim 8, wherein the first end of said first tube is attached to theinner surface of the first plate and wherein the first end of saidsecond tube is attached to the inner surface of said second plate.
 10. Avariable-rate spring marine docking cable, comprising: a variable rate,helical compression spring member, the spring member having a proximateend, a distal end, an axial length and helical coils defining an innervolume; first and second round, metallic bars disposed in the innervolume, each of the metallic bars being U-shaped and having a base endand free ends, the free ends forming hooks engaging the correspondingend of the spring member; and cables extending from the base ends of thebars.
 11. The variable-rate spring marine docking cable according toclaim 10, wherein the base of said first metallic bar extends slightlybeyond the proximate end of said spring member and the free ends of saidfirst metallic bar are hooked onto the distal end of said spring member.12. The variable-rate spring marine docking cable according to claim 10,wherein the base of said second metallic bar extends slightly beyond thedistal end of said spring member and the free ends of said firstmetallic bar are hooked onto the proximate end of said spring member.13. The variable-rate spring marine docking cable according to claim 10,wherein the base of said first metallic bar extends slightly beyond theproximate end of said spring member and the free ends of said firstmetallic bar are hooked onto the distal end of said spring member andwherein the base of said second metallic bar extends slightly beyond thedistal end of said spring member and the free ends of said firstmetallic bar are hooked onto the proximate end of said spring member.